| Native starches have been widely used in some industries, however, their disadvantages found in reality have also greatly limited their applications in industry such as insolubility in cold water and loss of viscosity. For the application of starch, the traditional way is to heat the starch slurry to gelatinization. The pregelatinized starch showed graininess and poor taste. These influence their application seriously. Therefore, the preparation of granular cold water soluble starches is one of the best way to expanded the application of modified starch in industry. In this paper, maize starch as raw material, researched the effect of the different milling conditions. The properties such as granularity, crystal structure, the shape of granule, the transparency, retrogradation characteristics and freeze-thaw stability has been analyzed either. These studies provide a theoretical basis for the industrial production of granular cold water soluble starch.This experiment selected maize starch as raw material, researched the effect of the kinds of the pan, ratio of ball to material, fill ratio, milling speed and milling time. The results showed that PTFE pot is not suitable for the preparation of cold-water swelling starch. Used ceramic and stainless steel pot, cold water solubility of maize starch is73.31%and73.41%. The most suitable preparation for cold water soluble maize starch is ceramic pot.With ball milling, the particle size of cold water soluble maize starch was increased significantly. The amorphous structure was affirmed by X-ray diffraction techniques, which showed that the degree of crystallization decreased with the cold water solubility increasing for the three kinds of pot. The shape of GCWS starch granule was investigated with scanning electron microscope, which showed the surface of the cold water soluble maize starch has layered structure, but it retained its granule.Some properties of modified maize starch were studied. Experiments indicated that compared with the native maize starch, the modified maize starch prepared by ceramic pot and stainless steel pot ball milling showed higher transmittance, initial viscosity, lower retrogradation and freeze-thaw stability. The properties of modified maize starch prepared by PTFE pot ball milling did not change significantly compared with native maize starch.Therefore, the granular cold water soluble starch, which cold water solubility above70%has been prepared. The potential value of ball-milling technology has been found. |
PDF Full Text Request